Abstract
Providing secure and high-speed data transmission for low-orbit aircraft (LOA) is a priority in today's world. The objective of this study is to modify existing encryption methods for LOA to overcome the disadvantages in speed and vulnerability to emerging cyber-attacks, including quantum ones. The main idea is to develop a hybrid approach combining an optimized lightweight stream cipher ChaCha20 with a quantum key distribution protocol BB84. This will provide high encryption speed and information-theoretic key exchange security, which is invulnerable to quantum attacks. The research methodology includes the analysis of existing cryptographic solutions, performance modeling of the proposed hybrid algorithm, and the integration of machine learning-based anomaly detection mechanisms (LSTM) to improve the robustness of the system. The main results show that the proposed method significantly improves throughput, reduces latency and power consumption compared to traditional approaches, while providing resilience to current and future threats. The value of the work lies in contributing to the development of post-quantum cryptography for the aerospace industry and creating a basis for the development of more secure and efficient NOLA communication systems, which has direct practical implications for environmental monitoring, precision agriculture and national security.